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Gemini 3.7 Flash vs GPT-6 Sol

vs

Which one, when

Both models cover chat, vision, code, tools and reasoning with roughly a million tokens of context (1048576 for gemini-3.7-flash, 1050000 for gpt-6-sol), so the split is mostly price, modalities and output room. Pick gemini-3.7-flash for cheaper high-volume work at $0.75 input and $3.75 output per million, about 2.7x less than gpt-6-sol on both, and when you need audio or video inputs, which it accepts and gpt-6-sol does not. Pick gpt-6-sol at $2 input and $10 output when you want up to 128000 output tokens per response or the ability to turn thinking off.

Benchmarks

Above averageNo peer higherGemini 3.7 Flash17 / 243 / 24GPT-6 Solonly 4 comparable
Gemini 3.7 Flash GPT-6 Sol other models measured peer average no peer scored higher
DeepSWE 1.1
65.3%
68.8%
BioMysteryBench hard
43.5%
N/A
OSWorld 2.0
47.9%
N/A
Finance Agent v2
59%
N/A
Harvey Lab-AA
90.7%
N/A
HLE-Verified
53.6%
N/A
AutomationBench (v1.0.6)
52.3%
33.2%
LVBench
no peer scored higher 85.4%
N/A

Vendor-published: Alibaba (Qwen) Anthropic DeepSeek Google Moonshot OpenAI Tencent Z.ai

Pricing

Gemini 3.7 Flash GPT-6 Sol Δ
Input / 1M tokens $0.75 $2 0.38×
Output / 1M tokens $3.75 $10 0.38×
Cache read / 1M tokens $0.075 $0.2 0.37×
Cache write - no separate charge -

Rates from the live catalog at build time; each model page carries the current card.

Where they sit - input price per 1M tokens across all 74 chat models on this billing unit (log scale)

Gemini 3.7 Flash · $0.75 GPT-6 Sol · $2
$0.05 · Qwen3 VL Flash $30 · GPT-5.4 Pro

Capabilities

Gemini 3.7 Flash GPT-6 Sol
Tool use yes yes
Thinking control yes - vendor dial not published configurable
Structured output yes yes
Prompt caching implicit + explicit implicit (automatic)
Cache lifetime not published 5-10m, up to 1h
Minimum cached prefix 4096 tokens 1024 tokens

Specs

Gemini 3.7 Flash GPT-6 Sol
Input modalities text image audio video text image
Output modalities text text
Released 2026-08-13 2026-09-22
Knowledge cutoff 2026-03 2026-04
Context window 1M 1.1M
Max output 66K 128K
Thinking parameter - reasoning.effort
Accepted values -
reasoning.effort
  • none
  • low
  • medium
  • high
  • xhigh
  • max
Default - medium

Specs are transcribed from each vendor’s documentation; a row a vendor does not publish is left out rather than inferred. Full sources: Gemini 3.7 Flash · GPT-6 Sol

One prompt, both models - measured through the gateway

PROMPT Explain to a CFO, in exactly three sentences, why our LLM bill doubled after we enabled reasoning. CHECK exactly 3 sentences

Gemini 3.7 Flash passed · 3 sentences

Enabling reasoning causes the model to generate a high volume of invisible "thinking tokens" behind the scenes to deliberate and solve complex logic before delivering a final response. Because our vendor bills strictly on token volume, this additional internal computation effectively doubled our billable output per query. In short, our costs increased because we are now paying for the extra compute capacity required to produce significantly higher-accuracy answers.

out 878 tok (+799 thinking) latency 6.9 s

GPT-6 Sol passed · 3 sentences

Enabling reasoning made the model generate extra internal tokens to work through each request, and those tokens are billed even though users don’t see them. If request volume stayed roughly the same, more billed tokens per request could explain why the bill doubled. We should check the usage breakdown to confirm, then lower reasoning effort or limit it to tasks that need it.

out 188 tok (+111 thinking) latency 5.0 s

Instruction following (exactly three sentences - countable), audience shaping (CFO register), and the hidden-thinking billing gap the token meters below expose.

PROMPT This function is supposed to return the longest run of consecutive equal items, but callers report it is off by one on single-element inputs and misses runs that end at the last index. Fix it and explain the bug in one paragraph. CHECK fix passes tests

Gemini 3.7 Flash passed · 8/8 cases

Here is the corrected function: ```python def longest_run(xs): if not xs: return 0 best = 1 cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` ### Explanation of the Bug The original function tracked equal adjacent transitions instead of the actual number of elements in a run, causing all non-empty run lengths to be undercounted by one (e.g., returning `0` instead of `1` for single-element lists because the loop never executes, and `1` instead of `2` for pairs). Initializing both `best` and `cur` to `1` (after handling empty inputs) and resetting `cur` to `1` on a mismatch ensures every individual element is counted as a valid run of at least length one.

out 1050 tok (+827 thinking) latency 6.4 s

GPT-6 Sol passed · 8/8 cases

```python def longest_run(xs): if not xs: return 0 best = cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` The original `cur` counted matching *adjacent pairs*, not items, so every run was one too short—including a single-element input, which returned 0. Starting each run at 1 counts its first item, and updating `best` on every iteration ensures a run that reaches the last index is included.

out 206 tok (+59 thinking) latency 5.9 s

Whether the fix is actually correct (runnable), explanation density, and token efficiency on a bounded task.

PROMPT Extract a JSON object with fields {company, quarter, revenue_usd_m, growth_pct, guidance} from this text. Use null for anything not stated; add no other fields. CHECK valid JSON, schema exact

Gemini 3.7 Flash passed · 5/5 fields, guidance "withheld"

```json { "company": "Meridian Robotics", "quarter": "September quarter", "revenue_usd_m": 412, "growth_pct": null, "guidance": "withheld" } ```

out 918 tok (+858 thinking) latency 6.2 s

GPT-6 Sol passed · 5/5 fields, guidance "Withheld pending the Q4 close"

{"company":"Meridian Robotics","quarter":"September quarter","revenue_usd_m":null,"growth_pct":null,"guidance":"Withheld pending the Q4 close"}

out 227 tok (+185 thinking) latency 5.2 s

Schema obedience (no invented fields), hallucination pressure (guidance is explicitly withheld), and structured-output path differences.

PROMPT Write a 120-word product announcement for an API gateway feature that caches prompts across providers. Forbidden words: "seamless", "unlock", "game-changer", "revolutionize", "empower". Exactly one sentence must be a question. CHECK 120 words, 0 banned words

Gemini 3.7 Flash passed · 120 words, 0 banned, 1 question

Why pay twice for identical AI queries simply because you routed them to different model vendors? Today, we introduce Universal Prompt Caching directly within our unified API gateway architecture. This capability stores repeated prompt contexts across OpenAI, Anthropic, and local models, instantly returning stored results to eliminate redundant computation fees. When your application sends an LLM request, the gateway inspects the payload, identifies semantic matches, and returns accurate cached responses in under ten milliseconds. Engineering teams can now slash inference latency by eighty percent while dramatically reducing monthly token expenditures across diverse production deployments. You retain complete privacy control, flexible cache eviction policies, and granular metrics through a single dashboard. Update your routing settings today to accelerate overall system performance.

out 2858 tok (+2718 thinking) latency 14.1 s

GPT-6 Sol passed · 120 words, 0 banned, 1 question

Today, we’re introducing cross-provider prompt caching for our API gateway, helping teams reuse repeated prompt content when routing requests among supported AI providers. The gateway identifies eligible prompt prefixes, stores cache references, and applies them to subsequent requests where provider capabilities allow. Why send the same context again if it can be reused? With fewer duplicate input tokens, applications can reduce costs and improve latency without changing how developers call the gateway. Configure caching by route, monitor hit rates and savings in your dashboard, and keep existing provider fallback rules in place. Availability and cache behavior vary by provider, so the gateway reports eligibility and usage for each request. Get started today with our documentation and test your existing workloads.

out 586 tok (+443 thinking) latency 7.7 s

Constraint obedience (word budget, banned-word list, the single question), style fingerprint, and length control.

Switch between them with one line

Both ids are in every tab below - the highlighted pair of lines is the only edit. Same endpoint, same key, same request shape.

from openai import OpenAI

client = OpenAI(
    base_url="https://synthorai.io/v1",
    api_key="sk-syn-...",
)

resp = client.chat.completions.create(
    model="gemini-3.7-flash",
    # model="gpt-6-sol",  # uncomment this line, comment the one above
    messages=[{"role": "user", "content": "Summarize this diff"}],
    reasoning_effort="medium",
)
print(resp.choices[0].message.content)

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FAQ

Which is cheaper, Gemini 3.7 Flash or GPT-6 Sol?

Gemini 3.7 Flash is cheaper on input / 1m tokens ($0.75 vs $2, 2.7× apart). Other rows may point the other way - the table above carries the full card, and real cost depends on your mix.

Can I A/B test Gemini 3.7 Flash against GPT-6 Sol without two integrations?

Yes. Both are served through the same OpenAI-compatible endpoint with one API key - switching is a one-line model-string change, so you can route a fraction of traffic to each and compare bills directly.

Do Gemini 3.7 Flash and GPT-6 Sol support prompt caching?

Yes - both bill cached reads below their input rate, so warm-prefix workloads cost less than the list rates suggest. The exact cache-read rows are in the pricing table above.

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